Other, P- 40 = 4
Where the primary measuring device does not fit one of the three other categories,
P-40 may be programmed for one or two head versus flow characterizations:
» P-40 = 4 : curved
» P-40 = 5 : linear
Select the characterization which most closely fits the flow characteristics of the
primary measuring element.
Characterization is achieved by entering the head ( H parameter ) and corresponding
flow ( F parameter ) either from emperical measurement or from the manufacturer’s
specification. The more breakpoints that are defined, the more accurate will be the
flow measurement. Breakpoints should be concentrated in areas exhibiting the higher
degrees of non linear flow. A maximum of eleven breakpoints can be defined.
Head data is entered in the linear units selected ( P-1 ) and flow data is entered in the
desired units of flowrate.
Other Flumes Example
The application is to measure the flow across a 4 ft rectangular weir with end
contractions. The flow is characterized by the following formula:
cfs = 3.33 ( L-0.2H ) H
1.5
where: cfs = flow in cu ft / sec
L = length of crest
H = head
linear
curved
Head
F
l
o
w
PL-443 6 – 39
To Next Page
Loading...
Need help?
General
